Dialysis catheter and methods of insertion

ABSTRACT

A method of inserting a dialysis catheter into a patient comprising the steps of inserting a guidewire into the jugular vein of the patient through the superior vena cava and into the inferior vena cava, providing a trocar having a lumen and a dissecting tip, inserting the trocar to enter an incision in the patient and to create a subcutaneous tissue tunnel, threading the guidewire through the lumen of the trocar so the guidewire extends through the incision, providing a dialysis catheter having first and second lumens, removing the trocar, and inserting the dialysis catheter over the guidewire through the incision and through the jugular vein and superior vena cava into the right atrium.

[0001] This application claims priority from provisional patentapplication serial No. 60/260,592, filed Jan. 9, 2001, the entirecontents of which is incorporated herein by reference.

BACKGROUND

[0002] 1. Technical Field

[0003] This application relates to a catheter and more particularly to amulti-lumen dialysis catheter and over the wire methods of insertion ofthe dialysis catheter.

[0004] 2. Background of Related Art

[0005] Hemodialysis is a well known method of providing renal (kidney)function by circulating blood. The kidneys are organs which function toextract water and urea, mineral salts, toxins, and other waste productsfrom the blood with filtering units called nephrons. From the nephronsthe collected waste is sent to the bladder for excretion. For patientshaving one or both defective kidneys, the hemodialysis procedure is lifesaving because it provides a machine to simulate the function of thekidneys.

[0006] In the hemodialysis procedure, blood is withdrawn from thepatient's body through a catheter or tube and transported to a dialysismachine, also commonly referred to as a kidney machine. The catheter istypically inserted through the jugular vein and maneuvered into positionthrough the superior vena cava into the right atrium to provide highblood flow. In the dialysis machine, toxins and other waste productsdiffuse through a semi-permeable membrane into a dialysis fluid closelymatching the chemical composition of the blood. The filtered blood, i.e.with the waste products removed, is then returned to the patient's body.In some instances, the catheter may be left in place for several years.As can be appreciated, proper access to the patient's blood andtransport of the blood to and from the dialysis machine for thisextended period of time is critical to hemodialysis.

[0007] One example of a dialysis catheter currently being marketed isthe MedComp Ash Split catheter. This catheter has two lumens, one forarterial flow and the other for venous flow, which are each D-shaped incross-sectional configuration. The catheter is bifurcated at its distalend to separate the lumens and the catheter is manually split to thedesired length for selected separation before insertion into the targetarea. Another well-known catheter is a Med Comp catheter which has thevenous flow lumen terminating proximally, i.e.. axially recessed, fromthe arterial flow lumen. Each of these lumens is also D-shaped incross-sectional configuration.

[0008] These Medcomp dialysis catheters require numerous steps forinsertion. The multiple insertion steps can be summarized as follows:

[0009] 1. an introducer needle is inserted through a first incision site(first opening) to properly locate (access) the vessel, e.g. the rightinternal jugular vein;

[0010] 2. a guide wire is inserted through the needle into the internaljugular vein and down through the superior vena cava into the inferiorvena cava;

[0011] 3. the introducer needle is withdrawn leaving the guidewire inplace;

[0012] 4. a tear away (peel away) sheath and dilator are inserted overthe guidewire and through the first incision site to provide an accessport for the dialysis catheter into the jugular vein, superior vena cavaand right atrium;

[0013] 5. a second incision is made in the chest wall to create a secondopening;

[0014] 6. a trocar is attached to the distal end of the dialysiscatheter;

[0015] 7. the trocar and dialysis catheter are pushed through the secondincision and advanced to bluntly dissect the subcutaneous tissue to exitthe first incision (opening) which was created by the introducer needle,thereby creating a subcutaneous tissue tunnel between the first andsecond openings;

[0016] 8. the trocar is detached from the dialysis catheter leaving thecatheter in place extending from the second opening, through the tissuetunnel and out the first opening;

[0017] 9. the dilator and guidewire are removed, leaving the tear awaysheath in place in the first incision which has been expanded by thedilator;

[0018] 10. the dialysis catheter, which is protruding from the firstincision, is inserted through the tear away sheath and advanced so itsdistal portion is positioned in the right atrium;

[0019] 11. the sheath is separated, i.e. split, by pulling the tabsapart, and then pulled upwardly away from the dialysis catheter andremoved from the body, leaving the catheter in place; and

[0020] 12. the second incision is closed and the dialysis catheter,which is connected through tubes to the dialysis machine, is left inplace an extended period of time to provide blood circulation to andfrom the dialysis machine.

[0021] (Alternatively, in the foregoing method, the trocar can be forcedthrough a third incision exiting adjacent the first incision, and theninserted through the introducer sheath positioned in the firstincision.)

[0022] This multiple step process of inserting the Medcomp dialysiscatheter is time consuming and complicates the surgical procedure. Thesemultiple steps add to the cost of the procedure, not only because of theadditional surgeon's time but because additional components, such as thetear-away sheath, are required which increases the overall cost of thecatheter system. Also, removal of the dilator increases the tendency ofthe sheath to kink causing difficulties in catheter insertion.

[0023] The use of the tear away sheath is also potentially problematic.The tear-away style sheath has lines of weakness to separate the sheathas it is pulled apart by the pull tabs to enable removal of the sheath.However, the sheath can potentially cause damage to the vessel wall asit is being pulled apart and can cause infection. Moreover, pulling thesheath laterally can enlarge the incision, thereby increasing thedifficulty of closing the incision at the end of the procedure. Also,since the sheath is pulled in the proximal direction for removal, itcould pull the catheter proximally as well, thereby pulling it away fromthe desired site, and requiring repositioning. The edges of the tearaway can also lacerate the surgeon's glove and finger.

[0024] An additional potential risk with utilizing tear away sheaths isthat air embolism can occur. During the time the surgeon withdraws thedilator from the sheath and inserts the catheter, a passageway throughthe sheath to the vessel is open. If the patient inhales during thiscatheter exchange, an air bubble can enter the vascular system andobstruct the vessel, potentially causing stroke or even death.

[0025] It would therefore be advantageous if a dialysis catheterinsertion method could be provided which reduces some of the foregoingprocedural steps, thereby decreasing the complexity of the procedure anddecreasing the hospital and surgeon costs. It would also be advantageousif such dialysis catheter insertion method could be provided which wouldbe less traumatic and avoid the foregoing problems associated with theuse of a tear-away sheath, such as increased risk of air embolism,trauma to the vessel wall, incision enlargement and dislodgement of thecatheter.

[0026] Another area of dialysis catheter insertion, which needsimprovement, is guiding the catheter to the target site. Dialysiscatheters are composed of flexible tubing to minimize damage to thevessel wall during insertion and use. This flexibility, however,oftentimes results in kinking of the catheter since the catheter mustnavigate curves to reach the target vessel. This kinking can adverselyaffect blood flow. Also, the catheter needs to have some degree ofstiffness to enable directing the catheter around the curves of thevessels. The stiffness, however provides its own risks since if thecatheter is not properly directed, the catheter can inadvertently beforced against the vessel wall, thereby puncturing or damaging thevessel. Several different approaches have been discussed in the priorart to increase stiffness of catheters such as providing a distal tip ofstiffer material to guide the catheter as in U.S. Pat. No. 5,957,893,using materials of different durometers in various portions of thecatheter (U.S. Pat. No. 5,348,536), placing an additional concentrationof material in the tip as in U.S. Pat. No. 4,583,968, or providingreinforcing strips, obturators or tubes within the catheter body toincrease the rigidity (e.g. U.S. Pat. Nos. 4,619,643, 4,950,2595,221,255, 5,221,256, and 5,246,430). The need however exists to improvethe balance between flexibility and stiffness. Thus it would beadvantageous to provide a catheter with sufficient flexibility toaccommodate anatomical curves of the patient while still havingsufficient stiffness to enable guiding the flexible catheter tubingatraumatically through the length of the vessels.

[0027] In navigating vessels to access the target site, such as theright atrium, it is desirable to provide the smallest catheter profile,i.e. the smallest outer diameter catheter body. This profile facilitatesinsertion through smaller vessels as it reduces the likelihood of thecatheter engaging the wall of the vessel and reduces trauma to thevessel by minimizing frictional contact with the vessel wall. However,the desire for smaller diameter catheters must be balanced against theneed for providing sufficient sized lumens to enable proper blood flow.If the lumens are too small, sufficient blood flow may not be able to bemaintained and the blood can be damaged during transport. Also, asufficient relationship must be maintained between the size of thelumens and the overall diameter of the catheter to maintain thestructural integrity of the catheter.

[0028] Numerous attempts have been made in the prior art to optimize themulti-lumen configuration. In some approaches, such as disclosed in U.S.Pat. Nos. 4,568,329 and 5,053,023, inflow and outflow lumen are providedside by side in D-shaped form. In other approaches, such as thosedisclosed in U.S. Pat. Nos. 4,493,696, 5,167,623 and 5,380,276 theinflow and outflow tubes are placed in concentric relation. Otherexamples of different lumen configurations are disclosed in U.S. Pat.Nos. 5,221,256, 5,364,344, and 5,451,206. The lumen configuration mustaccommodate two competing factors: keeping the catheter as small aspossible to facilitate insertion while keeping the lumens as large aspossible for blood flow. This balance must be achieved while maintainingthe structural integrity of the catheter. It would therefore beadvantageous to provide a catheter which reaches an optimum compromisebetween these two competing factors.

[0029] Another important feature of dialysis catheters is the suctionopenings to withdraw blood. Keeping the suction openings clear ofthrombolytic material and away from the vessel wall is clearly essentialto dialysis function since an adequate supply of blood must be removedfrom the patient to be dialyzed. However, a problem with prior dialysiscatheters is that during blood withdrawal, as suction is being appliedthrough the catheter openings and lumen, the suction can cause thecatheter to be forced against the side wall of the vessel, known as“side port occlusion”, which can block the opening and adversely affectthe function of the catheter by enabling only intermittent suction. Infact, the opening can become completely blocked, thereby preventingnecessary intake of blood, i.e. venous flow. Fibrin sheath growth aroundthe outside of the catheter can occur since dialysis catheters areoftentimes implanted for several months or even years. This fibringrowth, caused by the body's attempt to reject the catheter as a foreignbody, could result in blocking of the suction holes.

[0030] The need therefore exists for an improved dialysis catheter whichfacilitates the surgical dialysis procedure. Such catheter wouldadvantageously reduce the catheter insertion time, simplify the catheterinsertion process, eliminate the need for a peel-away introducer sheath,decrease the chances of infection, reduce unwanted kinking of thecatheter during insertion, strike an optimal balance between overallcatheter and lumen size, and improve the suction capability to avoidhampering of venous flow.

SUMMARY

[0031] The present invention overcomes the disadvantages anddeficiencies of the prior art. The present invention provides a methodof inserting a dialysis catheter into a patient comprising:

[0032] inserting a guidewire into the jugular vein of the patientthrough the superior vena cava, and into the inferior vena cava;

[0033] providing a trocar having a lumen and a dissecting tip;

[0034] inserting the trocar to enter an incision in the patient tocreate a subcutaneous tissue tunnel;

[0035] threading the guidewire through the lumen of the trocar so theguidewire extends through the incision;

[0036] providing a dialysis catheter having first and second lumens;

[0037] removing the trocar; and

[0038] inserting the dialysis catheter over the guidewire through theincision and through the jugular vein and superior vena cava into theright atrium.

[0039] The method preferably comprises the step of inserting a dilatorprior to the step of inserting the dialysis catheter. The methodpreferably further comprises the step of temporarily inserting astiffening member in the first lumen of the catheter to facilitateinsertion of the catheter. The method of inserting the stiffening memberand advancing the catheter preferably includes the steps of twisting thestiffening member and securing the stiffening member to a proximalportion of the catheter to stretch the catheter to reduce a least aportion of the outside diameter of the catheter.

[0040] Preferably, the method also comprises the steps of removing theguidewire and leaving the catheter in position for at least several daysto enable blood inflow through the first lumen and blood outflow throughthe second lumen to dialyze the patient's blood. The step of leaving thecatheter in place to enable blood outflow and inflow preferably furthercomprises the step of enabling blood outflow through at least oneopening in a wall of the catheter and enabling blood inflow through atleast one opening in a distal portion of the catheter.

[0041] Also provided is a method of inserting a dialysis catheter into apatient comprising:

[0042] inserting a guidewire into the vein of a patient;

[0043] advancing a trocar through an incision in the patient to create asubcutaneous tissue tunnel;

[0044] retracting the guidewire through the subcutaneous tissue tunneland incision utilizing the trocar;

[0045] removing the trocar;

[0046] inserting a dialysis catheter over the guidewire through theincision and subcutaneous tissue tunnel and through the vein of thepatient; and

[0047] securing the dialysis catheter to the patient.

[0048] The step of retracting the guidewire may comprise the step ofinserting the guidewire through an opening in the trocar. The openingmay extend longitudinally through the trocar and the step of insertingthe guidewire may comprise the step of threading the trocar over theguidewire such that the guidewire exits from a proximal portion of thetrocar.

[0049] The present invention also provides a method of inserting adialysis catheter into a right atrium of a patient is also providedcomprising:

[0050] providing a dialysis catheter having a lumen;

[0051] inserting a guidewire into the inferior vena cava of the patient;

[0052] inserting a stiffening member through the lumen in the catheter;

[0053] inserting a guidewire through the stiffening member and advancingthe dialysis catheter and stiffening member over the guidewire into thevein and into the right atrium of the patient; and

[0054] removing the guidewire leaving the dialysis catheter in place fora period of time.

[0055] The step of inserting the stiffening member preferably comprisesthe step of inserting the stiffening member such that a dilating distaltip of the stiffening member extends distally of the catheter.

[0056] The method preferably further comprises inserting a tunnelingmember through an incision to create a tissue tunnel and to retrieve theguidewire. Preferably the guidewire is inserted through a longitudinallyextending opening formed in the tunneling member. The dialysis catheteris preferably inserted subcutaneously over the guidewire through atissue tunnel prior to the step of advancing the dialysis catheter intothe vein.

[0057] The step of advancing the dialysis catheter over the guidewiremay include the step of forming a loop in the catheter corresponding toa loop formed in the guidewire prior to fully advancing the catheterinto the right atrium.

[0058] The present invention also provides a dialysis cathetercomprising a catheter body having a proximal portion, a distal portion,a first longitudinally extending central lumen configured to deliverblood, and at least three longitudinally extending lumens positionedradially of the central lumen and configured to withdraw blood from apatient. At least one blood delivery opening is formed in the distalportion of the catheter body and in fluid communication with the firstlumen and configured for passage of blood therethrough. At least threeblood withdrawal openings are formed in the outer wall of the catheterbody, wherein each of the openings is in fluid communication with one ofthe at least three lumens and is configured for passage of blood from apatient.

[0059] A stiffening member may be provided which is positionable withinthe catheter in abutment with a shoulder or threadedly attached in analternate embodiment. The stiffening member places the catheter body intension, and torquing the stiffening member stretches the catheter bodyto reduce at least a portion of an outer diameter of the catheter body.The stiffening member preferably includes a longitudinally extendinglumen for receiving a guidewire. A stiffening insert having a firststiffness greater than a second stiffness of the distal tip portion ofthe catheter can also be provided having a lumen formed thereincommunicating with the first lumen.

[0060] The distal tip portion of the catheter has a bullet noseconfiguration in one embodiment and tapers to a reduced diameter regionin another embodiment. In one embodiment, at least two side ports areformed in an outer wall of the distal tip portion and are in fluidcommunication with the first lumen of the distal tip portion andpositioned proximally of the stiffening insert.

[0061] The present invention also provides a system for placement of adialysis catheter comprising a tunneling trocar and a dialysis catheter.The system comprises a trocar having an elongated tubular portion and alumen extending longitudinally through the tubular portion. The tubularportion terminates in a dilating tip configured to dilate tissue andcreate a subcutaneous tissue tunnel. The lumen has a first internaldiameter configured to removably receive a guidewire therethrough forretrieval of the guidewire. The dialysis catheter has a first lumenconfigured for blood delivery and a second independent lumen configuredfor blood withdrawal from the patient. At least a portion of thecatheter has an outer diameter configured for insertion through thesubcutaneous tissue tunnel and one of the lumens is configured toreceive the guidewire for over the wire insertion of the dialysiscatheter through the tissue tunnel when the trocar is removed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Preferred embodiment(s) of the present disclosure are describedherein with reference to the drawings wherein:

[0063]FIG. 1 is a plan view of a first embodiment of the multi-lumencatheter of the present invention being inserted through the rightinternal jugular vein and superior vena cava into the right atrium of apatient's body;

[0064]FIG. 2 is a plan view illustrating the multi-lumen catheter ofFIG. 1 being inserted through the left internal jugular vein andsuperior vena cava into the right atrium;

[0065]FIG. 3 is an isometric view of the first embodiment of themulti-lumen catheter of the present invention and showing the directionof insertion of the stiffening rod;

[0066]FIG. 4A is a side view of a first embodiment of a stiffening rodof the present invention insertable through the catheter of FIG. 3 tofacilitate catheter insertion;

[0067]FIG. 4B is a side view of an alternate embodiment of thestiffening rod of the present invention having a series of mountingthreads at its distal end;

[0068]FIG. 5 is perspective view of the distal portion of themulti-lumen catheter of FIG. 3 and showing a guidewire extending throughthe central lumen;

[0069]FIG. 6A is a longitudinal cross-sectional view taken along lines6A-6A of FIG. 5;

[0070]FIG. 6B is a longitudinal cross-sectional view similar to FIG. 6Aexcept showing an alternate embodiment of the catheter having internalthreads for securing the stiffening rod of FIG. 4B;

[0071]FIG. 7 is a transverse cross sectional view taken along lines 7-7of FIG. 6A;

[0072]FIG. 8 is a transverse cross sectional view taken along lines 8-8of FIG. 6A:

[0073]FIG. 9A is a transverse cross-sectional view similar to FIG. 8except showing a second alternate embodiment of the lumen configurationof the catheter of the present invention;

[0074]FIG. 9B is a transverse cross-sectional view similar to FIG. 8except showing a third embodiment of the lumen configuration of thecatheter of the present invention;

[0075]FIG. 9C is a transverse cross-sectional view similar to FIG. 8except showing a fourth embodiment of the lumen configuration of thecatheter of the present invention;

[0076]FIG. 10 is a transverse cross-sectional view similar to FIG. 8except showing a fifth embodiment of the lumen configuration of thecatheter of the present invention;

[0077]FIG. 11 is a longitudinal cross sectional view of the distal endportion of the catheter of FIG. 3 illustrating the stiffening rod ofFIG. 4A being inserted through the central lumen of the catheter;

[0078]FIG. 12 is a longitudinal cross sectional view similar to FIG. 11except showing the stiffening rod fully positioned within the centrallumen, in abutment with the stop in the distal tip;

[0079] FIGS. 13-15 illustrate an alternate embodiment of the distal tipof the catheter of the present invention and the method steps forforming the tip wherein:

[0080]FIGS. 13A and 13B are perspective and cross-sectional views,respectively, of the tip before formation shown receiving a stiffeninginsert;

[0081]FIGS. 14A and 14B are perspective and cross-sectional views,respectively, of the tip once the stiffening inserted has been placedtherein;

[0082]FIGS. 15A and 15B are perspective and cross-sectional views,respectively, of the distal tip formed into a bullet nose configurationand showing side holes formed therein;

[0083]FIG. 16A is a perspective view of a distal portion of anotheralternate embodiment of the multi-lumen catheter of the presentinvention having a series of spacer wires and showing a guidewireextending therethrough;

[0084]FIG. 16B is a longitudinal cross-sectional view of the distalportion catheter of FIG. 16A showing the spacer wires in the extendedposition;

[0085]FIG. 16C is a longitudinal cross-sectional view similar to FIG.16A except showing the profile of the spacing wires and catheter bodyreduced as the stiffening rod of FIG. 4A is inserted into the centrallumen over the guidewire to stretch the catheter during insertion;

[0086]FIG. 17A is a perspective view of a distal portion of yet anotheralternate embodiment of the catheter of the present invention having aseries of integral spacer ribs;

[0087]FIG. 17B is a longitudinal cross-sectional view of the distalportion of catheter of FIG. 17 showing the spacer ribs in the extendedposition;

[0088]FIG. 17C is a longitudinal cross-sectional view similar to FIG.17A except showing the profile of the spacer ribs and catheter bodyreduced as the stiffening rod of FIG. 4A is inserted into the centrallumen to stretch the catheter during insertion;

[0089]FIG. 18 is a perspective view of a distal portion of anotheralternate embodiment of the multi-lumen catheter of the presentinvention having a tapered tip;

[0090]FIG. 19 is a longitudinal cross-sectional view of the distalportion of the catheter of FIG. 18 showing the stiffening rod positionedthrough the central lumen of the catheter over the guidewire;

[0091]FIG. 20 is a perspective view of a distal portion of yet anotheralternate embodiment of multi-lumen catheter of the present invention;

[0092]FIG. 21 is a perspective view of a first embodiment of a trocar ofthe present invention having a barbed proximal end for attachment to thecatheter for creating a subcutaneous tissue tunnel and for pulling thecatheter through the tissue tunnel;

[0093]FIG. 22 illustrates an alternate embodiment of the trocar of thepresent invention having a lumen for receiving a guidewire;

[0094]FIG. 23 illustrates the trocar of FIG. 22 being withdrawn after asubcutaneous tissue tunnel has been created;

[0095]FIG. 24A is a bottom view of another alternate embodiment of thetrocar of the present invention having a lumen for receiving aguidewire;

[0096]FIG. 24B is a longitudinal cross-sectional view of the distal endportion of the trocar of FIG. 24A,

[0097] FIGS. 25-28 illustrate the surgical method steps for insertingthe multi-lumen catheter of FIG. 3 through the right internal jugularvein and superior vena cava into the right atrium wherein:

[0098]FIG. 25 shows the introducer needle being inserted through theright jugular vein and the guidewire being inserted through the rightjugular vein, through the superior vena cava and into the right atrium;

[0099]FIG. 26 illustrates the needle introducer removed leaving theguidewire in place in the right internal jugular vein, superior venacava and right atrium;

[0100]FIG. 27 illustrates the trocar of FIG. 22 being inserted through afirst incision site and exiting a second incision site to create asubcutaneous tissue tunnel adjacent the incision site for the introducerneedle;

[0101]FIG. 28A illustrates the guidewire being threaded through thelumen of the trocar of FIG. 22;

[0102]FIG. 28B illustrates the trocar being removed, leaving theguidewire in place extending through the tissue tunnel; and

[0103]FIG. 28C illustrates the multi-lumen catheter of FIG. 3 insertedover the guidewire through the tissue tunnel, and curved down into theright internal jugular vein, superior vena cava and right atrium;

[0104] FIGS. 29A-29G illustrate the steps for an alternate method ofinserting the multi-lumen catheter of FIG. 3 through the right internaljugular vein and superior vena cava into the right atrium wherein thetrocar creates a tissue tunnel with an exit opening at the incision citewhere the needle and guidewire are introduced, wherein:

[0105]FIG. 29A illustrates the trocar of FIG. 22 inserted over theguidewire through a first incision site, creating a subcutaneous tissuetunnel, and exiting the incision site created for insertion of theintroducer needle and guidewire;

[0106]FIG. 29B illustrates the trocar being removed, leaving theguidewire in place extending through the tissue tunnel and forming aloop adjacent the needle incision site; and

[0107]FIG. 29C illustrates the multi-lumen catheter of FIG. 3 beinginserted over the guidewire for passage through the tissue tunnel;

[0108]FIG. 29D illustrates the catheter inserted through thesubcutaneous tissue tunnel and forming a loop corresponding to the loopformed in the guidewire,

[0109]FIG. 29E illustrates the catheter extending through thesubcutaneous tissue tunnel and being inserted further along theguidewire down into the right internal jugular vein;

[0110]FIG. 29F is a view similar to FIG. 29E except showing theguidewire being removed; and

[0111]FIG. 29G illustrates the catheter in place extending through thesubcutaneous tissue tunnel and advanced into the right internal jugularvein, superior vena cava and right atrium;

[0112]FIG. 30 illustrates an alternate method of retracting theguidewire through the subcutaneous tissue tunnel formed by the trocar;

[0113] FIGS. 31-37 illustrate a method for manufacturing a firstembodiment of the hub of the multi-lumen catheter of FIG. 3 wherein:

[0114]FIG. 31 illustrates a slit formed in the outer wall of thecatheter;

[0115]FIG. 32 is a view similar to FIG. 31 except showing in phantom thecentral arterial lumen of the catheter;

[0116]FIG. 33 is a transverse cross-sectional view taken along lines33-33 of FIG. 32;

[0117]FIG. 34 illustrates a pin inserted through the slit in the outerwall of the catheter;

[0118]FIG. 35 illustrates the tubing inserted over the pin;

[0119]FIG. 36 illustrates the injection of soft material over the pinand catheter tube to form the catheter hub which retains the lumenconnector tubes in position;

[0120]FIG. 37 illustrates the hub resulting from the injection moldingprocess enabling one connector to communicate with the inflow (arterial)lumen and the other connector to communicate with the multiple outflow(venous) lumens;

[0121] FIGS. 38-40. illustrate an alternate embodiment of the hub of themulti-lumen catheter of FIG. 3 wherein;

[0122]FIG. 38 illustrates a perspective view of the proximal end of thecatheter body split into five segments to accommodate the separateconnector tubes;

[0123]FIG. 39 is a perspective view illustrating the connector tubesinserted into the respective lumens of the catheter body; and

[0124]FIG. 40 is a transverse cross-sectional view illustrating the cutsmade in the catheter wall to form the separate segments.

[0125]FIG. 41 is a perspective view of another alternate embodiment ofthe hub of the catheter of the present invention having the lumenconfiguration of FIG. 9C;

[0126]FIG. 42 is an exploded view of the hub and tube structure of FIG.41;

[0127]FIG. 43 is an enlarged perspective view showing the transition ofthe venous holes from a substantially oval to a substantially roundconfiguration at the flared proximal portion of the catheter; and

[0128]FIG. 44 is an enlarged perspective view showing the multi-lumenextension tube tapering proximally and transitioning from substantiallycircular venous holes to substantially triangular holes.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0129] Referring now in detail to the drawings where like referencenumerals identify similar or like components throughout the severalviews, the first embodiment of the catheter of the present invention isdesignated generally by reference numeral 10. The catheter 10 istypically inserted into an area of high velocity blood flow to ensuresufficient blood can be transported from the body for dialysis. FIG. 1illustrates the catheter 10 inserted through the right internal jugularvein “a”, into the superior vena cava “b”, and into the right atrium“c”; FIG. 2 illustrates the catheter 10 inserted into the left internaljugular vein “d”, into the superior vena cava “b” and into the rightatrium “c”. Insertion into the right atrium, from either the right orleft side provides the necessary high blood flow to the dialysismachine. Note that the catheter body (catheter tube) 11 is sufficientlyflexible to enable it to bend to accommodate the anatomical curves asshown.

[0130] Catheter 10 has a catheter body or catheter tube 11 having adistal end portion 31, a proximal end portion 33, and an intermediateportion 35. Distal portion 31 terminates in nose 32 which isillustratively substantially conical in shape. Proximal end portion 33includes hub 12, where the lumens formed within catheter tube 11 areconnected, i.e. transition, to the respective inflow and outflow tubes,16, 18, respectively, to enable return and withdrawal of blood fordialysis. Conventional tube clamps 17 and 19 cut off blood flow throughinflow and outflow tubes 16, 18 as desired. As used herein, the terms“inflow” and “outflow” refer to the direction of blood flow with respectto the patient's body such that “inflow” refers to flow from thedialysis machine and delivered to the body while “outflow” refers toflow withdrawn from the body and transported to the dialysis machine.

[0131] As shown, intermediate portion of catheter 10 extends throughsubcutaneous tissue tunnel “t”, and curves downwardly toward the targetsite, e.g. the right atrium. This tunnel “t” secures the catheter inplace for dialysis for a period of weeks, or even months, with fibrouscuff 36 (FIG. 3) enabling tissue ingrowth. The formation of the tunnel“t” and the insertion of the catheter 10 therethrough will be discussedbelow in conjunction with the discussion of the catheter insertionmethod.

[0132] It should be appreciated that although the catheter is shownemerging from the tissue tunnel “t” at a second incision site,preferably, the tissue tunnel would not have an exit opening at a secondsite but instead would exit through the same incision through whichinitial access is made by the needle and dilator into the internaljugular vein “a”. This is described in more detail below.

[0133] A series of lumens are formed in catheter tube 11 fortransporting blood to and from a dialysis machine. As is well known inthe art, a dialysis machine essentially functions as a kidney forpatients suffering from kidney failure. Blood is removed from thepatient and transported to the dialysis machine where toxins are removedby diffusion through a semi-permeable membrane into a dialysis fluid.The filtered blood is then returned through the catheter body to thepatient.

[0134] More specifically, and with reference to FIGS. 5, 6A, 7 and 8,details of the catheter lumens will now be described. Centrallongitudinal lumen 40 is formed within catheter tube 11, extends theentire length and is designed to transport filtered blood to thepatient. Lumen 40 is also configured to receive a guidewire 20 to directthe catheter to the desired position. Lumen 40 extends to nose 42, andterminates in region 37 where it aligns with central longitudinal lumen41 of nose 42. Central lumen 41 of nose 42 communicates with narrowedlumen 45, terminating in distal opening 47 to communicate with thepatient's body so blood can be delivered through distal opening 47.Lumens 41 and 45 also receive guidewire 20. Thus, lumen 40, lumen 41 andnarrowed lumen 45 together form a central lumen enabling blood to bedelivered from the dialysis machine to the patient. The transition fromlumen 41 into narrowed lumen 45, forms a stop or shoulder 43, thefunction of which will be described below.

[0135] Nose 42 also includes side arterial (delivery) openings 46 formedthrough the outer wall 44 wall in fluid communication with lumen 41,also functioning to return blood to the patient's body. Side openings orports 46 are preferably angled outwardly as shown to facilitate deliveryof blood in the direction of blood flow and lessen mechanical hemolysis.These additional openings help maintain the desired flow volume bydistributing the blood through multiple holes. Although only fouropenings are shown, it is contemplated that additional or fewer openingscan be provided and the openings can be axially displaced with respectto each other. Additional set(s) of openings can also be provided spacedproximally or distally from side openings 46.

[0136] In this embodiment, nose 42 forms the distal tip portion and iscomposed of a different material than the other portions of the catheterbody 11 and is welded or attached by other means to the catheter body11. The tip (nose) in this embodiment is composed of a stiffer materialto facilitate tunneling and blunt dissection through tissue. The nosecould alternatively be composed of a softer material, thereby being lesstraumatic upon contact with the vessel wall. However, in a preferredembodiment, the nose is composed of the same material as the catheterbody, having a small stiffener member embedded therein. Thisconfiguration is described in detail below in conjunction with FIGS.13-15.

[0137] Catheter 10 also has a series of venous (withdrawal) lumens 34a-34 e, extending longitudinally along the length of the catheter body11, each terminating at surface 48 of nose 42. In the preferredembodiment, shown in the cross-sectional view of FIG. 8, the lumens 34are oval-like in configuration, with opposite curved walls 37 a, 37 band opposite substantially flat walls 39 a, 39 b. These spaced apartlumens have solid material between them therefore increasing thestructural integrity of the catheter body 11. The lumens 34 a-e areindependent from one another through the distal, intermediate andproximal portions 33, 35, 31 of the catheter body 11, until the hub 12where the lumens 34 a-34 e connect to a common connector tube. This isdescribed in more detail below. Lumens 34 a-34 e, as shown, aresymmetrically positioned and radially displaced from the centralarterial lumen 40.

[0138] With continued reference to FIGS. 5 and 6A, a series of sideopenings or ports 50 are provided in the outer wall 14 of catheter body10. These openings 50 a, 50 b, 50 c, 50 d, and 50 e are each in fluidcommunication with a respective outflow lumen 34 a-34 e and are designedand configured to withdraw blood from the patient's body for delivery tothe dialysis machine. A second set of openings 52 a-52 e, spacedproximally from openings 50 a-50 e, is also in communication with arespective lumen 34 a-34 e, Only three of the side openings 50,52 areshown in FIG. 5, it being understood that the other three openings arepositioned on the other side of the catheter, preferably symmetricallyplaced to accommodate the circumferential arrangement of the venouslumens 34 a-34 e.

[0139] Although lumens 34 a-34 e are isolated along a substantial lengthof the catheter, they preferably have a common flow source at theproximal portion 33 of the catheter 10. This is described in more detailbelow.

[0140] In the embodiment of FIG. 8, the arterial lumen size preferablyranges from about 0.006 inches to about 0.008 inches in cross-sectionalarea, and is more preferably 0.007 inches. The cross-sectional area ofeach of the venous lumens 34 preferably ranges from about 0.002 inchesto about 0.004 inches, and more preferably about 0.003 inches, bringingthe total cross-sectional area of the venous return lumens to about 0.01inches to about 0.02 inches, and more preferably about 0.015. This meansthat the ratio of total cross sectional area of the arterial lumen tothe venous lumen is about 1 to about 2.1. Other dimensions are alsocontemplated.

[0141] It should be appreciated that although five separate lumens 34are shown, a fewer or greater number can be provided. Also, although twosets of side openings are shown (set 50 and set 52), a fewer or greaternumber of sets can be provided, and a fewer or greater number ofopenings in each set could be provided.

[0142] Alternative lumen configurations spaced circumferentially areillustrated in FIGS. 9A, 9B, 9C and 10. In FIG. 9B, three arc-shapedlumens 60 a, 60 b, 60 c are positioned around the arterial central lumen40′. These larger sized lumens provide for additional venous flow butresult in the reduction of the strength of the catheter wall due to theless wall material as compared to the lumen configuration of FIG. 8. InFIG. 9A, five lumens 66 a, 66 b and 66 c are provided. These lumens havemore of a rectangular (or trapezoidal) shape with one pair of opposingwalls having a straighter configuration than the lumen configuration ofFIG. 8. As shown, the other pair of opposing walls has a slightcurvature. In FIG. 9C, four oval-like venous lumens 76 a, 76 b, 76 c,and 76 d are positioned around a substantially square central lumen 78.This lumen configuration provides for a substantially sized centrallumen and sufficient room between the central lumen 78 and each of thevenous lumens 76 a-76 d for the catheter walls to flex. In FIG. 10, fivelumens 70 a-70 e of circular cross-section are provided around thecentral lumen 40″, adding to the stability of the catheter by increasingthe wall material, but reducing the overall venous lumen size ascompared to the embodiment of FIG. 8. Preferably, the venous lumens ineach of these embodiments are independent from one another along thesubstantial length of the catheter.

[0143] Fewer or greater number of lumens could be provided and lumens ofother configurations are also contemplated. This positioning of thevenous lumens in a circle-like array around the catheter, i.e. radiallydisplaced from the center of the catheter, more evenly distributes thevacuum, as compared to a side by side venous/arterial lumenconfiguration, and ensures constant return flow since if one of thelumens becomes stuck against the vessel wall or otherwise clogged, theremaining lumens will maintain adequate flow. The openings in thesidewalls communicating with the lumens can also be elongated instead ofcircular, creating a series of longitudinally extending openings forentry of suctioned blood. This version of elongated openings is shownfor example in FIGS. 18 and 20 described in detail below.

[0144] To facilitate insertion, the catheter is configured to receive astiffening member in the form of a stiffening rod which stretches thecatheter to reduce its profile to aid in over the wire insertion andbetter navigate through small vessels. That is, the stiffening rod isinserted into central lumen 40 of catheter 10 and torqued to stiffen theflexible catheter for ease in over the wire insertion and navigationthrough the small vessels, and to reduce the outer diameter of thecatheter body by stretching it during insertion. After placement of thecatheter 10, the stiffening rod is removed, allowing the catheter toreturn to its higher profile position with the lumens of the necessarysize for blood transport to and from the body. Two embodiments of thestiffening rods are illustrated in FIGS. 4A and 4B and are shown priorto insertion into the catheter 10 in FIG. 3.

[0145] Turning to the first embodiment of the stiffening rod illustratedin FIG. 4A, the stiffening rod is designated generally by referencenumeral 80. Stiffening rod 80 has a distal tip 82, a proximal endportion 85 and an internal lumen 87 extending therethrough (see FIG.11). Stiffening rod 80 is inserted through the proximal end of inflowtube 16, in the direction of the arrow of FIG. 11, over the guidewire 20(which extends through lumen 87 and through central lumen 40 untildistal tip 82 abuts shoulder or stop 43 as shown in FIG. 12. Theproximal end portion 85 of stiffening rod 80 has a threaded portion 81which is screwed onto screw thread 15 of inflow tube 16. Thistemporarily secures the stiffening rod 80 within the catheter 10 duringinsertion. This threaded mounting requires the stiffening rod 80 to bemanually twisted, thereby torquing rod 80 as it presses forwardly andapplies a force against shoulder (abutment surface) 43 to stretch thecatheter body 11 to reduce its outer diameter. It is contemplated in oneembodiment, for example, that the catheter body 11 can be reduced indiameter from about 0.215 millimeters to about 0.207 millimeters by thestiffening rod 80. (Other size reductions are also contemplated). Thisreduction in catheter body diameter or profile is represented by thearrows D1 and D2 in FIGS. 11 and 12, respectively, which show the changein dimension effectuated by the stiffener rod 80.

[0146] After the catheter 10 is positioned at the desired site, thestiffening rod 80 is unthreaded from the proximal thread 15 of inflowtube 16 and removed from the central lumen 40 of the catheter 10 andfrom the inflow tube 16, thereby allowing the catheter to return to itsnormal profile of FIG. 11.

[0147] It should be appreciated that stiffening rod 80 can alternativelybe temporarily attached at its proximal end to the inflow tube 16 byother means such as a bayonet lock, snap fit, etc. The rod could firstbe manually twisted and then mounted by these various means forretention its torqued position.

[0148] An alternate embodiment of the stiffening rod is illustrated inFIG. 4B and designated generally by reference numeral 90. Stiffening rod90 has a threaded distal end 92 which is threaded onto internal threads251 of catheter 200 shown in FIG. 6B. A series of proximal threads 91are screwed onto the threads 15 of the inflow tube 16 in the same manneras described above for stiffener rod 80. The stiffening rod 90 functionsin the same manner as stiffening rod 80, i.e. to stretch the catheterduring insertion to reduce its profile and to stiffen it to facilitateinsertion, the only difference being the mechanical threaded attachmentof the distal end of the stiffening rod 90 to the catheter 200 insteadof the abutting relation of stiffening rod 80 with shoulder 43 ofcatheter 10. Preferably, the distal threads 92 are first threaded ontointernal thread 251, followed by attachment of the proximal threads 91as the stiffening rod 90 is torqued. Stiffening rod 90, like stiffeningrod 80, is preferably circular in cross-section, although otherconfigurations are also contemplated.

[0149] Catheter 200 of FIG. 6B is identical to catheter 200 in allrespects except for the threads 251 instead of shoulder 43 and lumen 241which is uniform in diameter. Similar to catheter 10, catheter 200 hasdistal opening 247 and outflow side openings 246 in outer wall 244communicating with lumen 241 in distal tip portion 242, whichcommunicates with central lumen 40. Venous inflow lumens 234 a-234 eterminate at wall 248 and have respective side openings 252 a-252 e and250 s-250 e formed in the outer wall 214. Only one of the side openings250 a, 252 a are shown in the longitudinal cross-sectional view of FIG.6B.

[0150] As noted above, distal tip (nose) can be composed of a differentstiffer material than the catheter body 11 or can be composed of amaterial having a higher durometer than the catheter body. This stiffermaterial will facilitate both tunneling through and dilating tissue. Inan alternate preferred embodiment, however, the distal tip is composedof the same material as the catheter body but has a stiffening insert.

[0151] More specifically, the alternative nose (tip) configuration isillustrated in FIG. 15, with the method of manufacturing the tip shownin FIGS. 13 and 14. This nose or distal tip 104, is composed of the samematerial as the catheter body 108 and has a stiffening insert 110inserted through central lumen 106 of nose 104. Central lumen 106extends through the catheter body. The stiffening insert 110 ispreferably composed of the same material as the catheter body 11 andnose 104, except it is made of a harder durometer material such as 72shoreD vs. 85 shoreA for the catheter body 11. The material utilized canbe, by way of example, urethane. For convenience, only the distal tip isshown, the remaining portions of the catheter 100 being identical tocatheter 10.

[0152] The stiffening insert 110, preferably cylindrical as shown, has ahole 112 for receipt of the guidewire and for communication with centrallumen 106. Insert 110 engages the inner wall surface 114 of centrallumen 106. Lumen 106, proximal of side openings 119, will include eithera stepped portion to provide an abutment surface (shoulder) forstiffening rod 80 or internal threads to mount rod 90 as describedabove.

[0153] The method of manufacturing this bullet shaped nose 104 will nowbe described in conjunction with FIGS. 13-15. Once cylindrical tube isformed, preferably by injection molding techniques, with centralarterial lumen 106 and venous lumens 109 a-109 e, stiffening insert 110is placed within central lumen 106 at the distalmost end andsubstantially flush with the distalmost edge 102 of the cylindricaltube.

[0154] Once the stiffening insert or slug 110 is placed within centrallumen 106, the tube is formed into the bullet nose shape of FIGS. 15Aand 15B, by a conventional radiofrequency or other heating process whichallows the tip material to flow and form around the harder insert 110.After heating of the die and formation into this configuration, thematerial is cooled and thereby hardens to the configuration of FIG. 15as the material fuses to the insert 110. A conventional core pin (notshown) can be used, inserted through the hole 112 and central lumen 106during the forming process. When the material hardens, the pin iswithdrawn to maintain these openings. After the forming process, sideholes 114 are either cut or drilled through the wall 108 of catheter 100to communicate with lumen 106 in the same manner as side holes 46communicate with central lumen 40 of FIGS. 1-6.

[0155] FIGS. 16A-17C illustrate two alternate embodiments of thecatheter of the present invention having spacers to minimize contact ofthe catheter body with the vessel wall. Provision of these spacers isoptional. In the embodiment of FIGS. 16A-16C, catheter 150, similar tocatheter 10, has a distal portion having a nose 154, a central arteriallumen 156 which also receives a guidewire 20, and a series (e.g. 5) ofvenous lumens 160-160. Arterial lumen 156 communicates with lumen 151and narrowed lumen 153 of the nose 154, terminating in open distal end158. A plurality of side openings 159 communicate with lumen 151 andfunction in the same manner as side openings 46 of catheter 10. Venouslumens 160 each terminate at side openings 161, similar to side openings52 of venous lumens 34 of catheter 10. Although only one series of sideopenings 161 are shown, clearly additional arrays of side openings,positioned distally or proximally of side openings 161 could beprovided. The venous lumen configuration can also vary in a similarmanner as described above with respect to catheter 10. Thus, except forthe spacers, catheter 150 is identical to catheter 10.

[0156] A plurality of spacer wires 164 are embedded in the wall 169 ofthe catheter 150 and are secured at region 158 by adhesive or othersuitable means. In the normal configuration, spacer wires 164 bowslightly outwardly with respect to the outer wall 169 of the catheter150 to reduce the likelihood of contact with the vessel wall. When thestiffening rod 80 is inserted over guidewire 20 and through centrallumen 156, as shown in FIG. 16C, and edge 170 is forced against theabutment surface or stop 159, the catheter body is stretched and thespacer wires 164 stretch to a straightened position, substantially flushwith the outer surface of wall 169. This reduces the profile of thecatheter and ensures the spacer wires do not interfere with catheterinsertion. When the stiffener rod 80 is withdrawn, the catheter returnsto its normal position, and the spacer wires 164 bow outwardly as inFIGS. 16A and 16B. It should be appreciated that stiffening rod 90 canalso be used with catheter 150 and would function to reduce the profilein the same manner as rod 80. Catheter 150 would then be provided withinternal threads for mounting stiffening rod 90 as described above.

[0157] An alternative to spacer wires is illustrated in FIGS. 17A-17C.Catheter 180 is identical to catheter 150, except it is provided withintegral ribs 194 proximal of nose 184. That is, similar to catheter150, catheter 180 has a central arterial lumen 186 configured to receiveguidewire 20 and stiffening rod 80 or 90. Lumen 186 communicates withlumen 181 and narrowed lumen 183 of the nose 184 which terminates inopen distal end 188. Side openings 189 of nose 184 communicate withlumen 181. A series of independent venous lumens 190 are provided,terminating in side openings 192, similar to side openings 161 ofcatheter 150. Although only one series of side openings 192 are shown,clearly additional arrays, positioned proximally or distally of sideopenings 192 could be provided.

[0158] Spacer ribs 194 are formed by cutout portions in the wall 193 ofthe catheter 150. FIG. 17B illustrates the spacer ribs 194 in theirnormal position, outwardly bowed from the outer surface of the wall 193of the catheter body. FIG. 17C illustrates the straightened or retractedposition of the spacer ribs 194, where the ribs 194 are substantiallyflush with the outer surface of wall 193, after stiffener rod 80 of FIG.4A (or rod 90 of FIG. 4B)) is inserted through central lumen 186 tostretch the catheter 150 for insertion in the manner described above.

[0159]FIGS. 18 and 19 illustrate another alternative embodiment of thecatheter of the present invention. Catheter 500 has a distal tip 502with a tapered region 510 transitioning to a reduced diameter region504. The central lumen terminates in distal opening 506 for fluiddelivery. Unlike the previously described embodiments, the distalopening 506 is the sole fluid delivery passageway into the body.However, it is also contemplated that additional side holes could beprovided in the tip to provide additional arterial ports for blooddelivery to the patient.

[0160] A series of venous openings 508 (only two are shown in the viewof FIG. 18) are provided in the transition or tapered region 510 of thetip 502. These openings are elongated to provide additional area forsuctioning. Each of the openings 508 communicates with a respectivevenous lumen 510 formed in the catheter. The venous lumen configuration(and arterial lumen configuration) can be in the form of thoseillustrated in FIGS. 7-10, or other variations, as described above.

[0161] Stiffening rod 520 is shown positioned in the central lumen ofthe catheter 500. Rod 520 is similar to the rods 80 and 90 describedabove except it extends distally of the distal tip 502 of catheter 500,has a tapered distal end 524 to facilitate tunneling and dilatingtissue, and has a stepped portion to abut the internal structure of thecatheter 500. More specifically, guidewire 20 is shown extending throughthe central lumen of stiffening rod 520. The stiffening rod 520 isinserted through the central lumen of catheter 500 and the stiffeningrod 520 and catheter 500 are inserted over the guidewire 20, with thetapered tip 524 facilitating passage of the catheter as it dilatestissue.

[0162] Catheter 500 has a cylindrical insert 514 positioned in thedistal tip, similar to insert 110 of FIG. 13A. The insert 514 iscomposed of a stiffer material to stiffen the tip of the catheter 500 tofacilitate insertion. Insert 510 has an opening to receive stiffeningrod 520 as shown. Shoulder 526 formed by stepped portion 524 abuts theinsert 514, thereby functioning as a stop in a similar manner thatshoulder 43 acts as a stop for stiffening rod 80 shown in FIG. 11, thedifference being the shoulder is formed in the internal wall of thecatheter rather than on the stiffening rod. Stiffening rod 520 thus actsin the manner as the aforedescribed rods 80, 90, i.e. pressing againstthe catheter tip portion to stretch the catheter for insertion, inaddition to providing a tissue tunneling and dilation function.

[0163]FIG. 20 illustrates an alternative tip design of the catheter ofthe present invention. Catheter tip 602 has a bullet nose configuration,somewhat similar to the nose of FIG. 15, except having more of aprogressive taper. Catheter tip 602 also has a series of elongatedvenous holes 608 (only two are shown in the view of FIG. 20). In allother respects, e.g. stiffening insert, stiffening rod, distal blooddelivery opening 606, etc, catheter 600 is identical to catheter 500 ofFIG. 18.

[0164] The method of insertion of the catheter of the present inventionprovides an entire over the wire system. This is achieved by theprovision of trocar 300 illustrated in FIGS. 22 and 23. Trocar 300 has alumen 304 formed thererethrough (shown in phantom in FIG. 22)dimensioned for reception of guidewire 20. The lumen 304 extends theentire length of trocar 300, from a proximal opening 306 in handle 308to a distal opening 310 (shown in phantom in FIG. 22) on the undersideof the trocar 300 as viewed in FIG. 22. Distal opening 310 is adjacentthe distal tip 302, at the region where it bends slightly upwardly. Notethe lumen 304 of trocar 300 can be smaller than the outer diameter ofthe dialysis catheter, e.g. catheter 10, since it only needs to have aninternal diameter of about 0.045 inches to receive the guidewire. Thediameter of the catheter is typically 0.215 inches. The blunt distal tip302 of trocar 300 bluntly dissects tissue to create a subcutaneoustissue tunnel for subsequent securement of the catheter.

[0165]FIGS. 24A and 24B illustrate an alternate embodiment of thetrocar. Trocar 380 is similar to trocar 300 except for an elongated ovalentrance opening 382 to lumen 383 for the guidewire and a beveled tip384 to facilitate tunneling through tissue. The handle configuration 386is also slightly different.

[0166] One method of use of the catheter will now be described inconjunction with FIGS. 25 to 28. The method will be described forinserting catheter 10, however it should be appreciated that any of theaforedescribed catheters can be inserted in the same manner.

[0167] First, needle “N” is inserted into the internal jugular vein toproperly locate the vessel and a guidewire 20 is inserted through theneedle into the right internal jugular vein “a” and into the superiorvena cava “b” as shown in FIG. 25. The guidewire 20 is further advancedinto the right atrium “c”. The needle “N” is then withdrawn, leaving theguidewire 20 in place, extending out of the patient's body at theproximal portion 21.

[0168] Next, trocar 300 is inserted through a first incision “s” in thepatient, bluntly dissecting and tunneling under the skin, and forced outof the tissue at a second incision or site “u”, creating a subcutaneoustunnel “t” under the tissue as shown in FIG. 27. This provides a way tosecure the catheter as described below. Guidewire 20 is then threadedthrough lumen 304 of the trocar, with proximal portion 21 first insertedthrough trocar distal opening 310 so it emerges out of proximal opening306 as shown in FIG. 28A. Trocar 300 is then withdrawn from the body inthe direction of the arrow of FIG. 28B, leaving the guidewire 20 inplace as shown. Thus, guidewire 20 extends from the right atrium andsuperior vena cava, out through the right internal jugular vein andthrough the tissue tunnel “t”.

[0169] Catheter 10 is then threaded over the guidewire 20, with theproximal portion 21 of the guidewire 21 inserted through the distal tiplumen of the catheter, through the length of the central lumen, andthrough the hub 12 into the inflow tube 116 and out through fitting 15.The catheter 10 is thus threaded over the wire, through the tissuetunnel “t” where cuff 36 (not shown in FIG. 28C) is positioned in thetissue tunnel “t” to aid in securement of the catheter by enablingtissue ingrowth over a period of time. The catheter 10 is furtheradvanced over guidewire 20 down into the right internal jugular vein,into the superior vena cava, and into the right atrium. The guidewire 20is withdrawn in the direction of the arrow, leaving the catheter 10 inplace for use as shown in FIG. 28C. Note the stiffening member 80 or 90(not shown in FIG. 28C for clarity) is preferably utilized, i.e.inserted over the guidewire 20 through the fitting 15, inflow tube 16,hub 12, and central lumen 40 to help guide the catheter 10 as describedin detail above.

[0170] As can be appreciated, the catheter will be inserted in a similarfashion through the left internal jugular vein to be positioned asdepicted in FIG. 2. In this method, the subcutaneous tissue tunnel willbe formed on the left side as shown (FIG. 2), by the trocar 300, and thecatheter inserted over the guidewire through the subcutaneous tissuetunnel and through the left internal jugular vein and into the superiorvena cava and right atrium in the same way as described for right sideinsertion. It should be understood that any of the aforedescribedcatheters of the present invention can be inserted in this fashion.

[0171] An alternative method of insertion is illustrated in FIGS.29A-29G. In this method instead of forming a second incision siteadjacent the incision site through which the needle and guidewire areintroduced into the internal jugular vein as in FIG. 27, the trocar 300emerges from the needle/guidewire insertion site. Although catheter 10is shown, any of the foregoing catheters can be inserted in the samemanner.

[0172] In this method, the needle and guidewire are inserted in anidentical manner as illustrated in FIGS. 25 and 26. After removal of theneedle, the guidewire 20 is left in place extending outwardly from theincision site, designated by “w”. Next, as shown in FIG. 29A, trocar 300is inserted through a first incision (as in FIG. 27) to create asubcutaneous tissue tunnel; however, unlike FIG. 27, trocar 300 does notemerge at a second incision site “u”. Instead, trocar 300 is advancedsubcutaneously to the needle incision site “w”, and emerges through thesite “w” as shown. Thus, as shown in FIG. 29A, the distal end of trocar300′ exits incision site “w” alongside the guidewire 20.

[0173] Guidewire 20 is then inserted (threaded) through the opening introcar 300 as described above and then the trocar is withdrawn throughthe tissue tunnel “t” and out through the first incision “s”, pullingthe guidewire 20 through the tunnel. After the guidewire 21 is pulledthrough the tunnel “t” and out through incision “s”, the trocar 300 isremoved as shown in FIG. 29B, leaving the guidewire 20 in place. Notethe guidewire 20 is positioned to form a guidewire loop 22 to facilitateinsertion of the catheter as will be described below.

[0174] The catheter 10 is then advanced over the guidewire 20 (FIG.29C), through the tissue tunnel, and exiting incision site “w” into theinternal jugular vein “a” (FIG. 29D). The catheter 10, as shown, isformed into a loop 13, tracking the loop 22 of guidewire 20, and thenadvanced downwardly through the internal jugular vein, the superior venacava and into the right atrium. (FIG. 29E). The guidewire 20 is thenwithdrawn as shown in FIG. 29F, and the catheter 10 is pushed downwardlyand/or pulled back to straighten the loop to position the catheter asshown in FIG. 29G.

[0175] It should be appreciated that formation of the loop in theguidewire and the catheter is optional and the procedure can beperformed without the loop.

[0176]FIG. 30 shows an alternate embodiment of a trocar utilized toretrieve the suture and retract it through the subcutaneous tissuetunnel. Trocar 300′ is similar to trocar 300 of FIG. 29 except for theprovision of eyelet 312. The suture is threaded through the eyelet(shown as two small opposing holes in the wall at the distal end of thetrocar 300′) and the trocar is pulled proximally through the tissuetunnel to pull the suture out through incision “s”. As shown, the trocarextends through incision “w”, the same incision created for insertion ofthe needle and guidewire.

[0177] It should be understood that instead of an eyelet, a hook orother means can be provided on the trocar for holding the guidewire toenable pulling the guidewire through the tissue tunnel. That is, inthese versions, the guidewire is not threaded through the trocar lumen,but rather the trocar is utilized to pull (retract) the guidewirethrough the tissue tunnel.

[0178]FIG. 21 illustrates an alternative trocar used for a differentapproach to catheter insertion. This trocar, designated by referencenumeral 350, does not provide for an entire over the wire system,however it is used with an approach providing a partial over the wiresystem which eliminates the need for a tear way introducer sheath. Asdiscussed in the Background Section of this application, tear awayintroducer sheaths are currently being utilized to guide the dialysiscatheter through the vessels into the right atrium. To avoid theproblems associated with the tear away sheath, the catheter in thisalternate method, can be advanced over a guidewire which can be placedin the manner illustrated in FIGS. 25 and 26.

[0179] In this method, trocar 350 is attached to the distal end of thecatheter by insertion of barbed end 352 into a mating fitting. Othermeans for temporarily attaching the trocar are also contemplated.

[0180] Trocar 350 has a blunt distal tip 354 and is advanced through afirst tissue incision and out through a second tissue incision, bluntlydissecting tissue and forming a subcutaneous tissue tunnel in a similarmanner as described above, except without the guidewire. Since trocar350 is attached to the catheter, it pulls the catheter through thetissue tunnel, so it emerges out through the second incision. The trocar350 is then detached from the catheter. The catheter is then bent asnecessary and threaded over the guidewire into jugular vein, superiorvena cava, and right atrium.

[0181] Turning now to one method of manufacturing the hub of thecatheter, and with particular reference to FIGS. 31-37, a method isdisclosed which enables connection of the central arterial (delivery)lumen of the catheter with an inflow tube and fluid connection of thefive independent venous (withdrawal) lumens with a single outflow tubeto provide fluid connection through the connectors.

[0182] Turning first to FIG. 31, a longitudinal slit 201 is formed at aproximal portion of catheter tube 203. FIG. 32 shows the relationship ofthe slit 201 and the central arterial lumen 205 as the slit is formed tocommunicate with the central lumen 205. As can be appreciated from thecross-sectional view of FIG. 33, the slit 201 is formed in the wall 206of the catheter tube 203 between adjacent venous (withdrawal) lumens 209a-209 e. Next, a metal pin 207 is inserted through the slit 201 for themolding process. Outer plastic inflow tubing 210 is placed over themetal pin 207 as shown in FIG. 35 to ultimately communicate with thecentral lumen 205. Outer plastic outflow tubing 211 is also shownpositioned over the catheter tube 203 which will communicate with thevenous lumens 209.

[0183] Next, conventional injection molding techniques are utilized sothe soft plastic material flows around the catheter tube 203 and themetal pin 207 as shown in FIG. 36. Then, the material is cooled toharden, forming a hub 208, with the metal pin 207 removed to form lumen204. Lumen 204 has a narrowed region 202. As shown in FIG. 37, lumen 204fluidly connects lumen 207 of inflow tube 210 with the central lumen 205of the catheter. Lumen 212 of outflow tubing 211 communicates with thefive independent venous lumens 209.

[0184] FIGS. 38-39 illustrate another method for manufacturing thecatheter connections. In this method, catheter body 402 of catheter 400is separated into five segments 401 a-401 e at its proximalmost end,corresponding to each of the venous (withdrawal) lumens 403 a-403 e.FIG. 40 illustrates the five cuts 408 made in the catheter wall 407between the adjacent venous lumens 403 to form the five segments 401.

[0185] A separate outflow connector tube 412 a-412 e is positionedwithin a respective venous lumen 403 a-403 e and is connected to arespective segment 401 a-401 e by solvent bonding or pressure fit. Theproximal end of each connector tube 412 is positioned within outflowtube 414 which transports blood to the dialysis machine. Thus, bloodflows through the venous lumens 403, through each outflow connector tube401 and into a single outflow tube 414.

[0186] Inflow tubing 416 is connected to central arterial lumen byinflow connector tube 410 which is attached inside the arterial lumen bysolvent bonding or pressure fit. Note that inflow connector tube 410 ispositioned between the segments 401. It should be understood, that iffewer or larger number of venous lumens are provided, then an equalamount of outflow tubes would be utilized as the venous lumens would becut into the corresponding number of segments.

[0187] FIGS. 41-43 illustrate another alternate method for manufacturingthe hub of the catheter of the present invention. This hub andassociated tubing is illustrated for use with a catheter having thelumen configuration of FIG. 9C, although it can be utilized with otherlumen configurations as well.

[0188] A central lumen connector (intermediate) tube 702 is joined withcentral lumen 78 of catheter 700. Four venous connecting (intermediate)tubes 704 are connected to a respective venous lumen 76 a. These tubeseach have a lumen that is substantially circular in cross-section alongits length. The substantially circular lumens corresponds to thecross-sectional shape of the venous lumens within catheter 10 whichtransition from a substantially oval cross-sectional configuration to asubstantially circular cross-sectional configuration at the flaredproximal portion shown in FIG. 43. Note that arterial lumen 78 alsotransitions to a substantially circular cross-sectional configuration.

[0189] Each of the connector tubes 704 is connected to multi-lumenextension (outflow) tube 708 which provides outflow of blood to thedialysis machine. Extension tube 708 has a flared distal portion 711with four lumens 710, each configured for communicating with one of theconnector tubes 704. As shown, each of the lumens 710 has asubstantially circular cross-sectional configuration that transitions toa substantially triangular cross-sectional configuration towards theproximal portion.

[0190] Single lumen extension (inflow) tube 712, which provides inflowof blood to the patient, connects to connector tube 702. Tube 712 has atapered distal end 718 and its lumen 719 transitions from asubstantially circular cross-sectional configuration to a substantiallysquare configuration toward the proximal end. Molding of housing 716with the foregoing tubes forms the catheter hub. Conventional tubeclamps, such as clamps 17,19 of FIG. 1, are placed around tubes 708, 712for cutting off blood flow.

[0191] A rotatable suture ring 720 is placed around the catheter hub andpreferably has a planar surface 722 to sit substantially flush with thepatient's skin. Suture holes 724 are configured to receive sutures forattaching the ring (and thus the catheter) to the patient.

[0192] The catheters described above can optionally include a surfacetreatment on the exterior and/or the interior. The surface treatmentscan include for example, an hydrophilic coating to increase lubricityand facilitate insertion, a drug coating such as heparin or containingIIb, IIIa inhibitors, inert coating substances such as Sorins carboncoating, and/or active coatings such as a silver ion coating.

[0193] It should be appreciated that although the catheter is describedherein as a dialysis catheter for hemodialysis, the catheter disclosedherein could have other surgical applications, such as drug delivery orblood sampling. Moreover, features of the catheter, tip configurationsand lumen configurations can be utilized on other catheters.

[0194] While the above description contains many specifics, thosespecifics should not be construed as limitations on the scope of thedisclosure, but merely as exemplifications of preferred embodimentsthereof. Those skilled in the art will envision many other possiblevariations that are within the scope and spirit of the disclosure asdefined by the claims appended hereto.

What is claimed is:
 1. A method of inserting a dialysis catheter into apatient comprising: inserting a guidewire into the jugular vein of thepatient through the superior vena cava, and into the inferior vena cava;providing a trocar having a lumen and a dissecting tip; inserting thetrocar to enter an incision in the patient and to create a subcutaneoustissue tunnel; threading the guidewire through the lumen of the trocarso the guidewire extends through the incision; providing a dialysiscatheter having first and second lumens; removing the trocar; andinserting the dialysis catheter over the guidewire through the incisionand through the jugular vein and superior vena cava into the rightatrium.
 2. The method of claim 1, further comprising the step oftemporarily inserting a stiffening member in the first lumen of thecatheter to facilitate insertion of the catheter.
 3. The method of claim2, further comprising the steps of removing the guidewire and leavingthe catheter in position for at least several days to enable bloodinflow through the first lumen and blood outflow through the secondlumen to dialyze the patient's blood.
 4. The method of claim 3, whereinthe step of leaving the catheter in place to enable blood outflow andinflow further comprises the step of enabling blood outflow through atleast one opening in a wall of the catheter and enabling blood inflowthrough at least one opening in a distal portion of the catheter.
 5. Themethod of claim 2, wherein the step of inserting the stiffening memberincludes the steps of twisting the stiffening member and securing thestiffening member to a proximal portion of the catheter to stretch thecatheter to reduce at least a portion of the outside diameter of thecatheter.
 6. The method of claim 3, wherein the step of inserting thedialysis catheter includes the step of forming a loop in the catheterprior to full insertion into the right atrium.
 7. The method of claim 1,further comprising the step of inserting a dilator prior to the step ofinserting the dialysis catheter.
 8. A method of inserting a dialysiscatheter into a patient comprising: inserting a guidewire into the veinof a patient; advancing a trocar through an incision in the patient tocreate a subcutaneous tissue tunnel; retracting the guidewire throughthe subcutaneous tissue tunnel and incision utilizing the trocar;removing the trocar; inserting a dialysis catheter over the guidewirethrough the incision and subcutaneous tissue tunnel and through the veinof the patient; and securing the dialysis catheter to the patient. 9.The method of claim 8, wherein the step of retracting the guidewirecomprises the step of inserting the guidewire through an opening in thetrocar.
 10. The method of claim 9, wherein the opening extendslongitudinally through the trocar and the step of inserting theguidewire comprises the step of threading the trocar over the guidewiresuch that the guidewire exits from a proximal portion of the trocar. 11.A method of inserting a dialysis catheter into a right atrium of apatient comprising: providing a dialysis catheter having a lumen;inserting a guidewire into the inferior vena cava of the patient;inserting a stiffening member through the lumen in the catheter;inserting a guidewire through the stiffening member and advancing thedialysis catheter and stiffening member over the guidewire into the veinand into the right atrium of the patient; and removing the guidewireleaving the dialysis catheter in place for a period of time.
 12. Themethod of claim 11, wherein the step of inserting the stiffening membercomprises the step of inserting the stiffening member such that adilating distal tip of the stiffening member extends distally of thecatheter.
 13. The method of claim 12, further comprising the step ofadvancing the dialysis catheter subcutaneously over the guidewirethrough a tissue tunnel prior to the step of advancing the dialysiscatheter into the vein.
 14. The method of claim 11, further comprisingthe step of inserting a dilator to facilitate access to the rightatrium.
 15. The method of claim 11, further comprising the step ofinserting a tunneling member through an incision to create a tissuetunnel and to retrieve the guidewire.
 16. The method of claim 15,further comprising inserting the guidewire through a longitudinallyextending opening formed in the tunneling member.
 17. The method ofclaim 11, wherein the step of advancing the dialysis catheter over theguidewire includes the step of forming a loop in the cathetercorresponding to a loop formed in the guidewire prior to fully advancingthe catheter into the right atrium.
 18. The method of claim 15, furthercomprising the step of inserting a dilator prior to the step ofinserting a dialysis catheter.